Crypt() is Unix C library function used for hashing passwords
A hash function is any well-defined procedure or mathematical function that converts a large amount of data into a small datum, usually a single integer. For questions about the Twitter and Facebook # symbol, use hashtag
"The second hashing function is hash which supports many more algorithms and variants than crypt but does not support some algorithms that crypt does"
from question "Best way to secure user passwords in a mysql database?"
"Hash is newer and seems to support more hashing alogrithms than crypt"
from question "Hash() vs. crypt() function comparison"